1. Field of the Invention
The present invention relates to a medical image processing apparatus and a medical image processing method for generating a three-dimensional medical image used in image diagnosis, etc.
2. Description of the Related Art
Conventionally, there has been conducted image diagnosis for diagnosing diseases, etc. by acquiring a tomographic (slice) image of an organ, etc. of a human body using a modality (image acquiring apparatus) such as a CT scanner, an MRI apparatus, etc.
Further, a method of conducting diagnosis by generating a three-dimensional image of a predetermined organ, etc. based on an acquired tomographic image has been established, contributing to a precise and accurate diagnosis.
Such an image diagnosis involves a work of selecting a target portion to be diagnosed (so-called “region-of-interest”) from the image of an image-taken region, and then extracting the image of the selected region-of-interest (ROI). A typical way of selecting an ROI is to select a continuous region (one closed region with the same contour as the ROI) containing an arbitrary point designated by an operator using a scheme, such as flood fill. Unexamined Japanese Patent Application KOKAI Publication No. H6(1994)-70923 discloses another ROI selecting method by which an operator designates a region to be selected in such a way as to surround an ROI.
Apparently, the work of selecting an ROI highly depends on the operation by an operator. This is likely to result in selection of an unnecessary region or exclusion of a necessary region.
In case where the heart and vessels around the heart are an ROI, an operator first inputs an arbitrary point by, for example, clicking a position on the screen which corresponds to the heart and the vessels according to the continuous-region selecting method. Then, a continuous region containing the input arbitrary point is selected and extracted as an image showing the heart and vessels. In case of extracting a continuous region containing an input arbitrary point, when a part of a vessel is in contact with a portion other than an ROI, for example, such a part is also selected and extracted as a continuous region.
In the second method by which an operator designates a selection range, the operator designates the selection range in such a way as to encompass a portion which is an ROI. It is however very difficult to accurately select a delicate part like vessels around the heart. Either method brings about a shortcoming that a necessary part cannot be selected adequately.
When an ROI cannot be selected (designated) accurately, normally, a so-called “Undo” operation or so is taken to return to one previous operational state and make selection again. Therefore, the prior arts repeatedly perform a designating operation and an Undo operation to select and extract a target ROI.